Update update command for RHEL NIM install

[mjang]

Proposed changes

Missing command detail, based on feedback

Once we've clarified whether this applies to other commands, we'll move it from Draft to Review

The new command seems to work in my RHEL 9 VM

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[vvnginx]

Looks good! Ship it!

[ADubhlaoich]

Generally LGTM: approving despite the procedural discussion, so as not to block the PR beyond the 2 approvals requirement.